(1) Field of the Invention
The present invention relates to a constant-velocity joint with a tripod, of the type comprising a tulip and a tripod whose center pivots with radial freedom of movement against the base of the tulip and is held under axial prestress against this base by an elastic clip having a central part in the form of a cup. The cup comprises a base which is in contact with a facing surface in the center of the tripod, and a side wall from the peripheral edge of which extend legs, the free ends of which are joined to the tulip.
(2) State of the Prior Art
A joint of this type is described, for example, in the document FR-A-2,487,022. In the elastic clip used in this document in order to carry out the function of axially retaining the tripod, the base of the cup is substantially flat and constitutes a bearing table with which a spherical surface of the center of the tripod is in contact.
The elastic clip is a piece formed by the blanking and bending of an elastic metal sheet. Satisfactory bearing of the sphere of the tripod depends on the dimensions of the triangular bearing table with which the spherical center of the tripod is to remain in contact irrespective of the position of the tripod at the maximum angularity of the joint. The height of the equilateral bearing triangle is limited by the fact that, when the joint is at a maximum angle of steering lock, the end position of the roller with which one of the arms of the tripod is equipped fixes a given bending angle for the side wall of the cup relative to the base in the corresponding zone.
Moreover, in the case where the rollers of the tripod interact with substantially toroidal tracks formed in the tulip, the end position of the roller comes even closer to the axis of the joint, which means that the bending angle of the metal sheet must be increased. The bending radius which results from this requirement can become incompatible with the needs of the tripod to travel back and forth on the plane bearing table, there being a risk of the tripod bearing against the bending radius.